The present invention relates to an arrangement for estimating motion of picture elements of a picture forming part of a sequence of pictures to be processed, the arrangement having an input for receiving a sequence of source pictures, a motion determining circuit for supplying a first motion vector for all the picture elements of the pictures of the sequence to be processed, a coherence circuit for supplying a validation signal of the first motion vector and a selection circuit, controlled by the coherence circuit, for supplying a definitive motion vector on the basis of said first motion vector and at least one alternative motion vector.
Such an arrangement is described in the non-prepublished international Patent Application WO-A 89/10600 (PHF 88-532) U.S. patent application Ser. No. 460,326, filed Dec. 18, 1989. The prior art arrangement is used in a standards converter, which, more specifically, converts pictures appearing at a rate of 50 Hz into pictures having a rate of 59.94 Hz. It is also possible to convert the pictures of the rate of 50 Hz into pictures having a rate of 100 Hz, by means of such converters, to avoid the annoying flicker phenomenon on television sets.
The described arrangement comprises three memories for containing coherence vectors relating to three successive pictures to supply the validation signal. Although this arrangement is satisfactory, Applicants have realized that it can be improved by processing coherence vectors relating to a larger number of pictures.